Recently, touchpads that receive variety operation commands are well used. The touchpads detect an operation position on an operation panel when the operation panel is touched or pressed by a user. Some touchpads may further detect an operation pressure. The touchpads operate in one of several ways, including detecting a capacitance change, detecting a resistance change, detecting a deformation of a supportive portion of the operation panel and the like.
As disclosed in JP 2009-298285 A, the touchpad is equipped to a steering wheel of a vehicle so that a driver of the vehicle operates the touchpad in a driving state. In the driving state, the driver holds the steering wheel with hands.
When the driver operates the steering wheel, the driver may unintentionally touch the touchpad and a function corresponding to the touch on the touchpad may be activated. Compared with a device that activates a function when a predetermined operation pressure is applied to, such as a button switch, the touchpad activates the function corresponding to the touch on the operation panel more easily. Further, the functions to be activated by a touch on the operation panel include normal functions that do not substantially affect the driving of the vehicle and specific functions that may substantially affect the driving of the vehicle. For example, the normal functions may include changing a temperature of an air conditioning, changing a volume of audio device and the like. The specific functions may include turning on/off the audio device, canceling of a route guidance and the like. The normal functions do not substantially affect the driving of the vehicle when the normal functions are activated for one time by the unintentional operation of the user. However, the specific functions may substantially affect the driving of the vehicle when activated one time. Thus, it is necessary to reduce the unintentional activation of the specific functions that may substantially affect the driving of the vehicle.